In order to meet the demand for the protection of interior trim of automobiles against deterioration, which has been increasing with the recent trend to luxury of the interior trim, and to reduce the load of air conditioning, a green-tinted glass having ultraviolet and infrared radiation absorbing power has recently been proposed as window glass of automobiles.
For example, there has been known a green-tinted glass having an ultraviolet transmission reduced to about 38% or less and a total solar energy transmission reduced to about 46% or less while maintaining a visible light transmission of at least 70% for securing the vision from the inside of automobiles. There is a recent trend that a bluish green tint is preferred for such a green-tinted glass for automobiles.
It is known that the total solar energy transmission can be decreased by increasing the absolute amount of ferrous oxide (FeO) of the iron oxides introduced into a glass. Almost all of the conventional infrared radiation absorbing glasses have used this method.
On the other hand, various methods have conventionally been proposed as methods for decreasing ultraviolet transmission. For example, an infrared and ultraviolet radiation absorbing glass disclosed in JP-A-4-193738 (the term "JP-A" as used herein means an "unexamined published Japanese patent application") contains cerium oxide and titanium oxide. More specifically, the glass comprises, in % by weight, as basic glass components, 68 to 72% SiO.sub.2, 1.6 to 3.0% Al.sub.2 O.sub.3, 8.5 to 11.0% CaO, 2.0.to 4.2% MgO, 12.0 to 16.0% Na.sub.2 O, and 0.5 to 3.0% K.sub.2 O, and as coloring components, 0.65 to 0.75% Fe.sub.2 O.sub.3, 0.20 to 0.35% CeO.sub.2 and 0.2 to 0.4% TiO.sub.2.
The green-tinted ultraviolet radiation absorbing glass disclosed in JP-A-6-564668 comprises, in % by weight, basic glass components of soda-lime-silica glass and having incorporated therein 0.53 to 0.70% total iron oxide in terms of Fe.sub.2 O.sub.3, 0.5 to 0.8% CeO.sub.2, and 0.2 to 0.4% TiO.sub.2 as coloring components, wherein 30 to 40% of the total iron oxide in terms of Fe.sub.2 O.sub.3 is FeO.
Further, the green-tinted ultraviolet and infrared radiation absorbing glass disclosed in JP-B-6-88812 (the term "JP-B" as used herein means an "examined published Japanese patent application") comprises, in % by weight, as basic glass components, 65 to 75% SiO.sub.2, 0 to 3% Al.sub.2 O.sub.3, 1 to 5% MgO, 5 to 15% CaO, 10 to 15% Na.sub.2 O, and 0 to 4% K.sub.2 O, and as coloring components, 0.65 to 1.25% total iron oxide in terms of Fe.sub.2 O.sub.3, 0.2 to 1.4% CeO.sub.2, or 0.1 to 1.36% CeO.sub.2 and 0.02 to 0.85% TiO.sub.2.
Because cerium oxide is expensive, an ultraviolet and infrared radiation absorbing glass having a decreased cerium oxide content has also been proposed.
For example, JP-A-4-231347 discloses a green-tinted ultraviolet radiation absorbing glass having a basic glass composition of soda-lime-silica glass and further containing, in % by weight, as coloring components, more than 0.85% total iron oxide (T-Fe.sub.2 O.sub.3) in terms of Fe.sub.2 O.sub.3, with a FeO/T-Fe.sub.2 O.sub.3 ratio smaller than 0.275, and less than 0.5% CeO.sub.2.
The above-described conventional ultraviolet and infrared radiation absorbing glasses have an ultraviolet radiation absorbing power imparted by ultraviolet absorption due to Fe.sub.2 O.sub.3, CeO.sub.2 and TiO.sub.2 and interactions among them. Of these components, it is CeO.sub.2 that can enhance the ultraviolet radiation absorbing power best without giving a yellowish tint unfavorable as a glass for automobiles. However, CeO.sub.2 is expensive. Therefore, in order to minimize the amount of CeO.sub.2 used, compositions are controlled such that the CeO.sub.2 content is decreased and the decreased ultraviolet radiation absorbing power corresponding to such a decreased amount is compensated for by using Fe.sub.2 O.sub.3 and TiO.sub.2. However, the ultraviolet absorption of Fe.sub.2 O.sub.3 or the interaction between TiO.sub.2 and FeO is extended over the visible light region. Therefore, if one tries to increase the ultraviolet absorption of a glass, the transmission of visible light in the short wavelength region is also decreased, so that the glass has a yellowish tint.